Eraser



E. A. cLAvEY July 17, 1934.

ERASER Filed July 15 Patented July 17, 1934 i ERASER 'Edward A. Clavey, Park Ridge; Ill., assignor to Beckley-Cardy Company, Chicago, 111 a cnr..

poration of Illinois Q ,fl Application July 15,19a,seriamaseosze My invention relates to erasers of-the type used for removing chalk marks from blackboards. The mcstpopular form of commercial eraser is the so-called noiseless type. kIn this form of eraser, the old style Wooden back is avoided and :a structure formed substantially entirelyuoffelt isused. PatentNo. 1,173,847 shows an 4early successful Yform of this type of eraser.. ...In Patent No. 1,457,497, certain improvements thereon are shown. Although the eraser shown. in the latter patent represents an advance Jin the art and has been used satisfactorily, ithas disadvantages in so-me respects. Undersome conditionsit tends to lose its shape and theback sometimes has a` tendency to warp in such a way as to cause the felt strips to nare out in lfan shape. The crossv stitch arrangement also adds tothe expense involved in the manufacture of this type of eraser, but unless this cross-stitching is employed, the tendency for the back to warp is increased;v

The principal object of my present invention "is to improve erasers' of `the character shown in the two patents noted. y M 1 Another object is the'provision of an eraser of this" `character having a noiseless back which will not lwarp;

Another object is to simplify the construction and method of manufacturing an eraser of this type.

A still further object is to utilize a structure which will not require cross stitching or stitching running laterally through the felt strips.

Other objects and features of the invention will be apparent from a consideration of the following detailed description taken with the accompanying drawing wherein Fig. 1 is a perspective View of an eraser constructed in accordance with one embodiment of my invention;

Fig. 2 is a slightly enlarged transverse sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a perspective view showing another embodiment of the invention;

Fig. 4 is a slightly enlarged sectional view taken on the line 4-'-4 of Fig. 3;

Fig. 5 is a fragmentary enlarged perspective view showing a feature of the construction; and

Fig. 6 is a modified form of back with a canvas insert between two halves.

In accordance with the general features of my invention, IV employ'a back which includes a strip of relatively stiff brous material, such as for example the relatively` long fibre, soft, dense felt ordinarily employed for this purpose and which has'been soaked with some filling or stiifening material such as glue so as to give stiffness to the back. y l l Ivhave found that in the use of such backs, the felt portion will intime Warp or curl upwardly fromA handling and even fromlying in `stock without use. To overcome this objection I apply to the back, preferably by means of an adhesive,

a separate strip of an inelastic material, preferaloly a closely woveninelastic canvas, in such 65 a way as to prevent thecurling or warping of the feltV back'. i

" Referring now tothe form shown in Figs. 1 and 2, I employ a felt back plate or portion 10 which has been stiflened` as suggested above, and on the underside of this member I secure a strip of inelastic material 11, preferably canvas, by means of an adhesive l2. The adhesive may be a glue similarto the glue with which the member 10 isllled. The back also includes a strip 13,0f felt material which extends around the edges of the relatively stiff member 10 and has, depending portions 14 and 16 formed by stitching 17 and 18, respectively. This stitching, as shown, extends through two portions'of the strip Island through the relatively stiff member` l0to form a pair of `longitudinally extending shoulders which provide a grip for the hand.

Intermediate the strips 14 and 16 are additional strips 19. These strips are formed preliminarily in the manner indicated in Fig. 5. First a relatively wide strip approximately double the width of the strips 19 is partially cut through along the center line running longitudinally of the strip and then the strip is bent over on itself to form a connecting portion 19a having a thickness somewhat less than the original thickness of the felt strip. As noted, the resulting structure is generally in the form of a V or fork in which the individual strips 19 comprise the legs of the V and the portion 19a the apex between the legs. Two of these V-shaped members are employed in the form shown between the outer strips 14. and 16, and stitching 21 is then used to secure each composite strip assembly to the back.

In forming erasers of this kind, the preferred practive is to form a long eraser body which is subsequently cut to shorter lengths to form the final eraser. In attaching the strips, they can be spread or deflected in any suitable manner by a machine element to facilitate stitching. The preferred arrangement is to assemble the outside strip 13 which forms partof the back and subsequently to attach the strips 19 in position. In the drawing, I show the strips ared out ibs.

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slightly in a fan-shape in order more clearly to illustrate the construction. It is to be noted, however, that the tendency of the strips 14 and 16 is to press inwardly, and in actual practice this occurs with the result that all of the strips are substantially parallel with each other and there is no necessity for employing lateral stitching to hold the strips in proper relationship.

The form of the invention shown in Figs. 3 and 4 employs the same features as the form shown in Figs. 1 and 2. In this form, however, the greater portion of the back is made up of the usual felt member 26 which has been stiifened as before indicated, and the inelastic member 27,- preferably canvas, is secured tothe under side thereof by glue 28. Outer strips 29 are sewed directly to the back, the sewing passing throughA the canvas and felt portions. This is done by layingthese strips at against the back with their lower edges extending toward the center line of the back. `"Ihey are then sewed in place by means of stitching 31, after which the unattached ends are pulled away from the back so that they occupy substantially the position shown in the drawing. Inner strips 32 are formed as shown in Fig. 5 and as previously described in connection with Figs. 1 and V2, and are attached to the back by stitching 33. n This completes the assembly of this form of eraser.

f In the type of back shown in Fig. 6, I have insertedvthe canvas strip 27a between two felt p0rtions, preferably all glued together so that the canvas strip will prevent warping or curling up of the back. y

It will be understood that my invention is not restricted to the materials described. The term felt is used in the claims to cover broadly this type of material. While the relatively stii members such as 10 and 26 are preferably felt treated to form a stifened back, but which is noiseless, other relatively long llibre materials may be employed which will have a stiifening action but through which stitching caribe used. The inelastic member 11 may be any material which will have the requisite function in the assembly. A relatively light weight but closely Woven inelastic canvas is a preferred material and very good results attend its use. Mechanically this member has a bracing function which prevents warping or bending of a felt back having that weakness. Any inelastic exible fabric, either textile or metal, may be employed and a satisfactory substitute material for a densely woven inelastic fabric is, for example, a screen formed of Vrelatively ne wire.

Although I have described several forms of my invention, I contemplate employing other arrangements and therefore do not desire to be limited to the forms shown and described but aim to cover all that which comes Within the spirit and scope kof the appended claims.

What I claim as new and desire to protect by Letters Patent of the United States is:

l. An eraser comprising a back including a re1- atively stiff member of felt material normally adapted to be displaced from its normal plane when eraser strips are sewed thereto, a plurality oi felt eraser strips, stitching. attaching. the felt strips to the back, and an inelastic but vflexible fabric member secured to the back so as to substantially preventv displacement thereof from its normal plane.

2. An eraser comprising a back includingv ay felt portion normally adaptedto warp or bend, anv inelastic exible fabric member secured to one face of the felt portion to substantially prevent warping, and a plurality of strips of felt material sewed to the back against said inelastic member.

3. An eraser comprising a rectangular flat back of felt-like material normally adapted to warp from its normal plane,A a sheet of inelastic but flexible canvas intimately secured to one faceof the back so as to prevent such warping of the back, and a plurality of eraser strips secured to the back by sewing through the canvas sheet.

4. An eraser comprisingY a rectangular flat back of felt-likematerial normally adaptedy to warp from its normal plane, a sheet of metallic screen intimately secured to one face of the back. so as to prevent such warping of the back, and a plurality of eraser strips secured to the back by sewing through the metallic sheet.

EDWARD A. CLAVEY. v

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